What's with the "gems" Delaney finds aboard the "Felice Adventurero"?

Question

When James Delaney visits his newly bought and formerly Spanish ship in Taboo S01E02, he finds something between the floor planks that looks like gems or coloured stones:

Once he realizes that the ship actually is a former slave ship, he gets rather frantic, scratching and gathering those stones out from the planks, accompanied by flashbacks to his experiences during the sinking of the Influence.

But what are these and why were they scattered between the floor planks of the ship? If they were actual valuable gems, how did they get there and how did noone else take them yet? And is this related to its nature as a slave ship somehow? Or is this as much a mystery to Delaney and everyone else as it is to me? Furthermore, and related to this, how does this scene fit into the rest of the narrative? Is it, or the gems, ever taken up again or was this just a character moment for Delaney to be reminded of his past experiences with slave ships?

Answer 1

They are trade beads. They are just glass, so not really valuable; but during that time such beads were used in purchasing slaves. Delaney would have recognized these beads.

Trade beads (sometimes called aggry and slave beads) were otherwise decorative glass beads used between the 16th and 20th century as a token money to exchange for goods, services and slaves (hence the name).

https://en.m.wikipedia.org/wiki/Trade_beads

On the ship he’s just purchased, there are beads in-between the boards, and shackles on the walls.

http://www.tracking-board.com/taboo-review-episode-two/

It would be reasonable that the beads would bring back his slave ship experiences.

As pointed out on Reddit, this paints a picture of the ship hauling beads to Africa, and trading them to bring back slaves.

...large, solid colored beads were often called "Dogon Eggs", as they were extensively traded among the Dogon people of Mali, West Africa in the 18th and 19th century Spice Trade. The beads were carried into Mali via early Dutch Traders and were sometimes also referred to as Dutch East India Company Trade Beads.

https://beadsofparadisenyc.com/products/lg-white-bohemian-wound-dogon-eggs